Add a method BrokerDuplicateSharedMemoryHandle() to the sandbox.

content/common/sandbox_init_win.cc

Index: content/common/sandbox_init_win.cc
diff --git a/content/common/sandbox_init_win.cc b/content/common/sandbox_init_win.cc
index 16e3e4afbd4a66e9ecf75903fcb2209820119d8d..dc5ac84e88512fd60a410ff8b697e9b8646aa6c5 100644
--- a/content/common/sandbox_init_win.cc
+++ b/content/common/sandbox_init_win.cc
@@ -42,4 +42,12 @@ bool InitializeSandbox(sandbox::SandboxInterfaceInfo* sandbox_info) {
   return InitTargetServices(target_services);
 }
 
+bool BrokerDuplicateSharedMemoryHandle(
+    base::SharedMemoryHandle source_handle,
+    base::ProcessId target_process_id,
+    base::SharedMemoryHandle* target_handle) {
+  return BrokerDuplicateHandle(source_handle, target_process_id, target_handle,
+                               0, DUPLICATE_SAME_ACCESS);
+}
+
 }  // namespace content